bectl(8): Implement bectl list -s

be_get_dataset_snapshots has been added to libbe(3), effectively returning
the same information as be_get_bootenv_props but for snapshots of the given
dataset. The assumption is that one will have the BE dataset name before
wanting to grab snapshots.

lib/libbe/be.h

@@ -68,6 +68,7 @@ const char *be_root_path(libbe_handle_t *);
 
 int be_get_bootenv_props(libbe_handle_t *, nvlist_t *);
 int be_get_dataset_props(libbe_handle_t *, const char *, nvlist_t *);
+int be_get_dataset_snapshots(libbe_handle_t *, const char *, nvlist_t *);
 int be_prop_list_alloc(nvlist_t **be_list);
 void be_prop_list_free(nvlist_t *be_list);
 

lib/libbe/be_info.c

@@ -29,6 +29,8 @@
 #include "be.h"
 #include "be_impl.h"
 
+static int snapshot_prop_list_builder(zfs_handle_t *hdl, prop_data_t *data);
+
 /*
  * Returns the name of the active boot environment
  */
@@ -117,6 +119,25 @@ be_get_dataset_props(libbe_handle_t *lbh, const char *name, nvlist_t *props)
 	return (ret);
 }
 
+int
+be_get_dataset_snapshots(libbe_handle_t *lbh, const char *name, nvlist_t *props)
+{
+	zfs_handle_t *ds_hdl;
+	prop_data_t data;
+	int ret;
+
+	data.lbh = lbh;
+	data.list = props;
+	data.single_object = false;
+	if ((ds_hdl = zfs_open(lbh->lzh, name,
+	    ZFS_TYPE_FILESYSTEM)) == NULL)
+		return (BE_ERR_ZFSOPEN);
+
+	ret = snapshot_prop_list_builder(ds_hdl, &data);
+	zfs_close(ds_hdl);
+	return (ret);
+}
+
 /*
  * Internal callback function used by zfs_iter_filesystems. For each dataset in
  * the bootenv root, populate an nvlist_t of its relevant properties.
@@ -221,6 +242,13 @@ prop_list_builder(prop_data_t *data)
 	return (0);
 }
 
+static int
+snapshot_prop_list_builder(zfs_handle_t *hdl, prop_data_t *data)
+{
+
+	return (zfs_iter_snapshots_sorted(hdl, prop_list_builder_cb, data));
+}
+
 
 int
 be_prop_list_alloc(nvlist_t **be_list)

lib/libbe/libbe.3

@@ -144,6 +144,9 @@ of state to be retained, such as errors from previous operations.
 .Ft int
 .Fn be_get_dataset_props "libbe_handle_t *, const char *, nvlist_t *" ;
 .Pp
+.Ft int
+.Fn be_get_dataset_snapshots "libbe_handle_t *, const char *, nvlist_t *" ;
+.Pp
 .Ft void
 .Fn be_prop_list_free "nvlist_t *" ;
 .\" .Ft void

sbin/bectl/bectl.c

@@ -74,6 +74,7 @@ static int bectl_cmd_add(int argc, char *argv[]);
 static int bectl_cmd_jail(int argc, char *argv[]);
 static const char *get_origin_props(nvlist_t *dsprops, nvlist_t **originprops);
 static void print_padding(const char *fval, int colsz, struct printc *pc);
+static int print_snapshots(const char *dsname, struct printc *pc);
 static void print_info(const char *name, nvlist_t *dsprops, struct printc *pc);
 static void print_headers(nvlist_t *props, struct printc *pc);
 static int bectl_cmd_list(int argc, char *argv[]);
@@ -505,6 +506,28 @@ dataset_space(const char *oname)
 	return (space);
 }
 
+static int
+print_snapshots(const char *dsname, struct printc *pc)
+{
+	nvpair_t *cur;
+	nvlist_t *props, *sprops;
+
+	if (be_prop_list_alloc(&props) != 0) {
+		fprintf(stderr, "bectl list: failed to allocate snapshot nvlist\n");
+		return (1);
+	}
+	if (be_get_dataset_snapshots(be, dsname, props) != 0) {
+		fprintf(stderr, "bectl list: failed to fetch boot ds snapshots\n");
+		return (1);
+	}
+	for (cur = nvlist_next_nvpair(props, NULL); cur != NULL;
+	    cur = nvlist_next_nvpair(props, cur)) {
+		nvpair_value_nvlist(cur, &sprops);
+		print_info(nvpair_name(cur), sprops, pc);
+	}
+	return (0);
+}
+
 static void
 print_info(const char *name, nvlist_t *dsprops, struct printc *pc)
 {
@@ -513,27 +536,34 @@ print_info(const char *name, nvlist_t *dsprops, struct printc *pc)
 	unsigned long long ctimenum, space;
 	nvlist_t *originprops;
 	const char *oname;
-	char *propstr;
+	char *dsname, *propstr;
 	int active_colsz;
 	boolean_t active_now, active_reboot;
 
+	dsname = NULL;
 	originprops = NULL;
 	printf("%*s%s", pc->current_indent, "", name);
+	nvlist_lookup_string(dsprops, "dataset", &dsname);
 
 	/* Recurse at the base level if we're breaking info down */
 	if (pc->current_indent == 0 && (pc->show_all_datasets ||
 	    pc->show_snaps)) {
 		printf("\n");
-		if (nvlist_lookup_string(dsprops, "dataset", &propstr) != 0)
+		if (dsname == NULL)
 			/* XXX TODO: Error? */
 			return;
 		pc->current_indent += INDENT_INCREMENT;
-		print_info(propstr, dsprops, pc);
+		print_info(dsname, dsprops, pc);
 		pc->current_indent += INDENT_INCREMENT;
 		if ((oname = get_origin_props(dsprops, &originprops)) != NULL) {
 			print_info(oname, originprops, pc);
 			nvlist_free(originprops);
 		}
+
+		/* Back up a level; snapshots at the same level as dataset */
+		pc->current_indent -= INDENT_INCREMENT;
+		if (pc->show_snaps)
+			print_snapshots(dsname, pc);
 		pc->current_indent = 0;
 		return;
 	} else
@@ -593,11 +623,8 @@ print_info(const char *name, nvlist_t *dsprops, struct printc *pc)
 	}
 
 	printf("\n");
-	if (originprops != NULL) {
-		/*if (pc->show_all_datasets) {
-		}*/
+	if (originprops != NULL)
 		be_prop_list_free(originprops);
-	}
 #undef BUFSZ
 }